As governments race to find a vaccine for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), public health experts are raising safety questions about the rapid development process, as well as concerns about public acceptance, equitable distribution, and timely access. Most vaccines take a decade or longer to come to market. Notably, the varicella vaccine took 28 years to develop, in contrast to the oft-cited timeline for a coronavirus vaccine of 12 to 18 months.
SARS-CoV-2 has also proven to be a perplexing virus, presenting challenges for vaccine development, especially about how to stimulate lasting immunity. In July, the New England Journal of Medicine published a letter to the editor regarding a small study of people who recovered from mild illness. Study participants began to lose antibodies to the disease within a few months of recovery and some did not develop antibodies at all. In mid-August, the New York Times reported on several emerging studies of T cells that showed evidence of a durable immune response in people who had recovered from COVID-19; a week later, however, the Times and others were reporting the story of a man in Hong Kong who had had the virus and was reinfected four months later. Despite these challenges, early results of vaccine trials have been encouraging and Dr. Anthony Fauci, the country's top infectious disease expert, has expressed cautious optimism about having a safe and effective vaccine by early 2021.
The short timetable for vaccine development was set by Operation Warp Speed, a $10 billion collaboration between the U.S. Department of Health and Human Services (HHS), the Biomedical Advanced Research Development Authority, and the U.S. Department of Defense. Private-sector initiatives are also underway. By late summer, there were over 165 vaccines in development worldwide, with 27 in human trials. In the United States, two vaccine developers launched large-scale efficacy trials, their final step before pursuing approval by the U.S. Food and Drug Administration (FDA). The biotechnology company Moderna began a phase 3 trial of its vaccine, mRNA-1273, and Pfizer, in partnership with the German immunotherapy company, BioNTech, began a combined phase 2-phase 3 trial of their vaccine, BNT162b2. Each trial aims to enroll up to 30,000 healthy adults-Moderna in the United States, and Pfizer and BioNTech in the United States and up to 120 additional sites worldwide. If trials go well, the vaccines could be submitted for FDA approval by the end of the year. To win approval, a SARS-CoV-2 vaccine must protect at least 50% of vaccinated people and meet the same safety standards as other vaccines.
But even if approved, will enough people trust in the safety and efficacy of a SARS-CoV-2 vaccine to receive it? So-called herd immunity for disease extinction requires between 55% and 82% of the population to be immune, either through prior infection or vaccination. The biggest barrier to achieving herd immunity via any vaccine is lack of public acceptance, which is looking to be a significant factor with this one. The breakneck pace of development has raised questions about safety. The FDA issued a press release in late June in which FDA commissioner Stephen M. Hahn pledged that while expediting the vaccine development approval process, the agency "will not cut corners in our decisions" nor sacrifice "standards for quality, safety, and efficacy."
Still, broad public acceptance of the vaccine is by no means assured. In a survey of 1,056 adults conducted in May by the Associated Press and the University of Chicago, only 49% of respondents said they planned to get vaccinated, while 20% said they would not and 31% were unsure. Among those who would not get vaccinated, 70% cited concerns about side effects as their main reason. The Centers for Disease Control and Prevention (CDC) is working with public health officials and advocates on educational campaigns to increase public confidence and counteract antivaccine messages on social media.
Another challenge is ensuring rapid and equitable access to a vaccine. As part of Operation Warp Speed, HHS is working with its partners to put an infrastructure in place capable of distributing 300 million doses of SARS-CoV-2 vaccine once it becomes available. Details of the distribution plan, however, are limited and, at times, confusing, according to an August report in the Washington Post, raising concerns among state and local health officials that they will be unable to immunize people quickly. In response to this uncertainty about action at the federal level, the National Governors Association has advised governors to begin their own preparations for vaccine distribution, including evaluating logistical capability and developing communication strategies to reduce vaccine hesitancy and improve uptake.
The CDC is working with its Advisory Committee on Immunization Practices to formulate recommendations for prioritizing vaccine distribution given the likelihood that initially there won't be enough doses for everyone. Consideration is being given to prioritizing vulnerable groups, including those in high-risk occupations such as health care workers and police, fire, rescue, and other first responders, and those at medical risk such as residents of long-term care facilities, people with chronic conditions, and adults 65 and older. Minority populations who have been disproportionately affected by the virus may also receive priority. Global access is also under discussion, however the United States announced in September that it would not join an international effort by the World Health Organization to develop and ensure equitable distribution of a vaccine.
Questions remain about the cost to governments and individuals. Companies that received government funding to develop a vaccine are required to allocate a certain number of doses to the government for free distribution to the public. And some pharmaceutical companies have pledged not to take a profit on any eventual SARS-CoV-2 vaccine. However, a lack of transparency about government contracts with the companies and how the vaccines will be priced has lawmakers calling for congressional oversight of the vaccine development and distribution process.
As COVID-19 continues to ravage the health and livelihoods of people across the globe, the promise of an effective vaccine can seem to be a magic bullet. However, a multitude of challenges remain, each needing thoughtful and ongoing discussion to ensure that vaccination programs are safe, effective, and equitable.-Karen Roush, PhD, RN, FNP-BC, news director